DEVICE ABSCNT

1. Introduction

The internal ABSCNT device manages the acquisition and manipulation of the position from absolute sensors. These sensors are typically absolute encoders with different types of output interface (parallel, SSI, etc.) The main features of the device are:

control of the data quality from the transducer
support for binary or gray encoding data
sexagesimal representation of read data (angles in degrees and early)
internal zero for the absolute position
generating an incremental count to be used by other devices

2. Declaration

For use the device you must declare it in the INTDEVICE section of the unit configuration.

;--------------------------------- 
; Internal devices Declaration
;--------------------------------- 
INTDEVICE 
...
<nome>  ABSCNT  TCamp  IAbsCont  ICont

Dove:

Field name	Description	Example	Note
<nome>	Device name	Axe	-
ANPOS2	Keyword that identifies the device ABSCNT	-	-
TCamp	Device sampling time in milliseconds	4	-
IAbsCont	Absolute counter number (Verify the HW documentation of the product for the correct value to set)	1
ICont	Incremental counter address generated by the device (always 1.CNTx)	1.CNT01	If entering the value X. X field is ignored

	All fields of the Declaration are mandatory and must be present on the same line. Set “X.X” or “X” if a resource is not available or cannot be used. Disable a resource means disable all functionality of the devices that use it.

3. Operation

Operation of the device is illustrated with the following diagram:

3.1 Communication configuration

The “Communication configuration” block Configure Protocol blocks appropriately in accordance with the number of bits to be captured, with the number of bits to “discard”, with the capture mode, etc.

3.2 SSI protocol interface

The “SSI protocol interface” block executes the acquisition of data from a transducer with SSI protocol. The read data should then be manipulated to get information by absolute position.

3.3 Communication error control

The “Communication error control” block does the control of the “quality” of data acquired by the transducer. Controls can be equal and/or, for transducers that require it, the verification of certain bits of error present in the frame.

3.4 Speed checking

The “Speed checking” block check the rotational speed in RPM compared to the maximum and shall report any overshoot. His task is to detect errors in the acquisition of the data.

3.5 Reversing

The “Reversing” block manages the reversal of direction of rotation that causes the increase in location determined byst_cntdir.

3.6 Module

The “Module” block manipulates the position acquired and subtracts the offset to bring it back within the range 0÷(pulserev x revnum) quando signenab be worth 0 and within the range -(pulserev x revnum)/2 ÷ (pulserev x revnum)/2 when signenab be worth 1.

3.7 Position conversion

The “Position conversion” block converts from value bits position at value position in units of measurement. The data obtained (posit) can have decimal or sexagesimal representation depending on the setting parameter posittype.

4. Notes on the device operation

It is possible to use the device for generating a virtual counter by setting the address ICont on the device declaration; because is the “virtual” counter you will always find in slot 1 (CPU ID). This feature makes it possible to use a translator of absolute type with counting and positioning devices that use incremental translators only (hardware resource CNTxx). Important: the “virtual” counter will update each device or sampling every 1ms depending on the setting of the parameter value updatemode.

When you set the sexagesimal representation the two least significant digits of the parameter posit indicate the 'minute', the other indicate the 'degrees'. With the sexagesimal representation, you must also set the parameters pulse and measure in particular on measure the value set must be in 'minute'. For example if we had an encoder with 10000 pulses and we wanted to get the angular position in 'degrees' and 'minutes' should set pulse=10000 and measure=360×60=21600.

5. Parameters list

5.1 prot

Short description	Protocol type
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷0
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Defines the protocol type used for acquisition of position transducer:

0= SSI

5.2 framebits

Short description	SSI Bits frame number
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷63
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Is the total number of bits that make up the SSI frame.

5.3 leadingbits

Short description	Non-significant bits in the SSI frame number
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷15
Parameter ID	-
Write conditions	st_updenab = 0

Description:

It is the number of bits, starting from the MSbit, which are meaningless for the reconstruction of the given by the transducer.

5.4 trailingbits

Short description	The frame number insignificant SSI frame queued
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷15
Parameter ID	-
Write conditions	st_updenab = 0

Description:

It is the number of bits, starting from the LSbit, which are meaningless for the reconstruction of the given position from the transducer.

5.5 codetype

Short description	Data code
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷1
Parameter ID	-
Write conditions	st_updenab = 0

Description:

It is the type of encoding of the data acquired by the position transducer:

0: Binary code
1: Gray code

5.6 datalogic

Short description	Logical data type
Dimension	Byte
Default value	Ritentive
Access type	Read
Unit measure	-
Valid range	0÷1
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Indicates the type of data captured by the transducer position:

0: normal
1: inverse

5.7 par

Short description	Parity check
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷2
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Indicates the type of parity check on SSI data:

0: disable
1: odd parity
2: even parity

5.8 parbitpos

Short description	Bit position equal
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷31
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Location of parity within the frame. This parameter is meaningful only if par > 0.

5.9 err1pos

Short description	Bit position error 1
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷31
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Bit position 1 error within the frame. Parameter that is currently not implemented.

5.10 err2pos

Short description	Bit position error 2
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷31
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Bit position 1 error within the frame. Parameter that is currently not implemented.

5.11 updatemode

Short description	Scan mode data
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷1
Parameter ID	-
Write conditions	st_updenab = 0

Description:

It is the temporal mode of acquisition of the transducer data:

0: each sample time device ABSCNT
1: continuous

5.12 clockrate

Short description	Clock frequency used from the SSI protocol
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷3
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Select the clock frequency used in SSI protocol:

0: 1MHz
1: 500KHz
2: 250KHz
3: 125KHz

5.13 monofloptime

Short description	Monoflop time
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	uS (microseconds)
Valid range	0÷127
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Indicates the time in monoflop microseconds. This is the time that waits between two acquisitions with SSI protocol, when updating the data is continuous(updatemode = 1). The set value will be rounded up to a multiple of the period of clock frequency (inverse of clockrate). If the value set is not obtainable from the device because they are too big and reports a warning.

5.14 pulserev

Short description	Number of positions per revolution
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷999999
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Number of positions per revolution of the transducer (plate data).

5.15 revnum

Short description	Number of turn
Dimension	Word
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷999999
Parameter ID	-
Write conditions	st_updenab = 0

Description:

It is managed by the transducer speed shown on the rating plate data. The value is significant when using multi transducers, for the transducers singleturn set the value 1.

5.16 signenab

Short description	Sign enabling
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷1
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Enables the interpretation of data acquired from the transducer with sign.

0: only positive position
1: positive and negative position

5.17 posittype

Short description	Representation posit parameter type
Dimension	Byte
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	0÷1
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Defines the representation type of the value of the parameter position posit:

0: decimal
1: sexagesimal (degrees and minutes)

5.18 measure

Short description	Reference measure for the position factor calculating
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	Um
Valid range	1÷999999
Parameter ID	-
Write conditions

Description:

Indicates the space, in units of measurement, routes to get primary impulses set in pulse parameter. This parameter is used to calculate the conversion factor between primary impulses and units.

posit = (encoder ⋅ measure) / pulse

The ratio measure/pulse must be a value between 0.00935 and 1.

5.19 pulse

Short description	Number of impulses for calculating the position factor
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range	1÷999999
Parameter ID	-
Write conditions	-

Description:

Indicates the number of pulses (1 encoder pulse = 4 primary pulses) that will generate the transducer in both directions to get a movement of measure. This parameter is used to calculate the conversion factor between primary impulses and units.

posit = (encoder · measure) / pulse

The ratio measure/pulse must be a value between 0.00935 and 1.

5.20 maxvel

Short description	Maximum speed
Dimension	Word
Default value	Ritentive
Access type	Read - Write
Unit measure	RPM
Valid range	0÷32767
Parameter ID	-
Write conditions	st_updenab = 0

Description:

Indicates the maximum speed expressed in revolutions per minute (RPM) where to ride is the position value in units corresponding to the impulses that are defined in pulserev. This parameter is used to control the quality of the value acquired by the transducer; basically the device check that between two consecutive values obtained there is a change in position “consistent” with the speed and that this variation does not exceed that which would be achieved when the transducer rotates the value set on the parameter. Setting value 0 disables the control.

5.21 encoder

Short description	Bit absolute position value
Dimension	Long
Default value	0
Access type	Read - Write
Unit measure	-
Valid range	-
Parameter ID	-
Write conditions	-

Description:

It is the bits value ( encoder positions) of the transducer absolute position. The value assumed by this parameter starts from 0 to(pulserev · revnum) when signenab be worth 0 and it goes -(pulserev· revnum)/2 to (pulserev · revnum)/2 when signenab be worth 1.

5.22 posit

Short description	UM value in absolute position
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	Um
Valid range
Parameter ID
Write conditions	-

Description:

It's the value expressed in units of absolute position of transducer. Is obtained by the following formula: encoder · measure / pulse.

5.23 par01

Short description	01 parameter
Dimension	Long
Default value	0
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Parameter 01. Not used, reserved for other use.

5.24 par02

Short description	02 parameter
Dimension	Long
Default value	0
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Parameter 02. Not used, reserved for other use.

5.25 par03

Short description	03 parameter
Dimension	Long
Default value	0
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Parameter 03. Not used, reserved for other use.

5.26 par04

Short description	04 parameter
Dimension	Long
Default value	0
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Parameter 04. Not used, reserved for other use.

5.27 ret01

Short description	retentive parameter 01
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Retentive 01 parameter. Not used, reserved for other use.

5.28 ret02

Short description	retentive parameter 02
Dimension	Long
Default value	Ritentive
Access type	Read - Write
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Retentive 02 parameter. Not used, reserved for other use.

5.29 errcode

Short description	Identification code of the error.
Dimension	Byte
Default value	0
Access type	Read
Unit measure	-
Valid range	-
Parameter ID	-
Write conditions	-

Description:

Indicates the type of error detected by the device. For more information see the section.

5.30 errvalue

Short description	Identifying the cause of the error code
Dimension	Byte
Default value	0
Access type	Read
Unit measure	-
Valid range	-
Parameter ID	-
Write conditions	-

Description:

Indicates the type of the error detected by the device. For more information see the section.

5.31 wrncode

Short description	Code warning identification
Dimension	Byte
Default value	0
Access type	Read
Unit measure	-
Valid range
Parameter ID	-
Write conditions	-

Description:

Indicates the type of warning reported by device. For more information see the section.

5.32 wrnvalue

Short description	Identification code of the cause of the warning
Dimension	Byte
Default value	0
Access type	Read
Unit measure	-
Valid range	-
Parameter ID
Write conditions	-

Description:

Indicates the cause of the warning reported by device. For more information see the section.

6. State lists

6.1 st_updenab

Short description	Enabling status update
Default value	0
Status ID	-

Description

Indicates that the acquisition of the data by the transducer is activated and adjusted by the parameter updatemode.

0 = acquisition disabled.
1 = acquisition enabled.

6.2 st_cntrev

Breve descrizione	Stato di direzione antioraria per l'incremento del conteggio.
Valore di default	Ritentivo
ID stato	-

Descrizione:

Indica la direzione di rotazione che causa l'incremento del conteggio.

0 = orario.
1 = antiorario.

6.3 st_warning

Breve descrizione	Presenza di un warning.
Valore di default	0
ID stato	-

Descrizione:

Indica lo stato di warning del device, per riconoscere il tipo di warning si deve fare riferimento alle variabili wrncode e wrnvalue.

0 = warning non presente.
1 = warning presente.

6.4 st_error

Breve descrizione	Presenza di un errore.
Valore di default	0
ID stato

Descrizione:

Indica lo stato di errore del device, per riconoscere il tipo di errore si deve far riferimento alle variabili errcode e errvalue.

0 = errore non presente.
1 = errore presente.

6.5 st_01

Breve descrizione	Stato Stato 1 generico
Valore di default	0
ID stato	-

Descrizione:

Stato disponibile per future implementazioni.

6.6 st_02

Breve descrizione	Stato Stato 2 generico
Valore di default	0
ID stato	-

Descrizione:

Stato disponibile per future implementazioni.

6.7 st_03

Breve descrizione	Stato Stato 3 generico
Valore di default	0
ID stato	-

Descrizione:

Stato disponibile per future implementazioni.

6.8 st_04

Breve descrizione	Stato Stato 4 generico
Valore di default	0
ID stato	-

Descrizione:

Stato disponibile per future implementazioni.

7. Elenco Comandi

7.1 UPDENAB

Breve descrizione	Abilitazione aggiornamento conteggio.
Condizione	st_updenab = 0
ID comando	-

Descrizione:

Abilita l'acquisizione del dato di posizione dal trasduttore in accordo con il parametro updatemode.

7.2 UPDDISAB

Breve descrizione	Disabilitazione aggiornamento conteggio.
Condizione	st_updenab = 1
ID comando	-

Descrizione:

Disabilita l'acquisizione del dato di posizione dal trasduttore.Con l'aggiornamento disabilitato è possibile modificare i parametri di comunicazione.

7.3 CNTREV

Breve descrizione	Direzione incremento conteggio antiorario.
Condizione	st_updenab = 0
ID comando	-

Descrizione:

Imposta la direzione di incremento del conteggio ad antiorario.

7.4 CNTDIR

Breve descrizione	Direzione incremento conteggio orario.
Condizione	st_updenab = 0
ID comando	-

Descrizione:

Imposta la direzione di incremento del conteggio ad orario.

7.5 RSERR

Breve descrizione	Reset dello stato di errore.
Condizione	st_error = 1
ID comando	-

Descrizione:

Azzera lo stato di errore (st_error) nel caso non sia più presente la condizione di errore.

7.6 RSWRN

Breve descrizione	Reset dello stato di warning.
Condizione	st_warning = 1
ID comando	-

Descrizione:

Azzera lo stato st_warning.

7.7 CMD01

Breve descrizione	Comando generico 1.
Condizione	-
ID comando	-

Descrizione:

Comando disponibile per future implementazioni.

7.8 CMD02

Breve descrizione	Comando generico 2.
Condizione	-
ID comando	-

Descrizione:

Comando disponibile per future implementazioni.

7.9 CMD03

Breve descrizione	Comando generico 3.
Condizione	-
ID comando	-

Descrizione:

Comando disponibile per future implementazioni.

7.10 CMD04

Breve descrizione	Comando generico 4.
Condizione	-
ID comando	-

Descrizione:

Comando disponibile per future implementazioni.

8. Errori e Warnings

8.1 Errors

Quando il device non riesce ad eseguire le operazioni derivanti da una non corretta programmazione da parte dell'utente segnala questa condizione tramite l'attivazione dello stato st_error. Il device, inoltre, rende disponibili, tramite i valori sui parametri errcode ed errvalue, alcune informazioni per meglio comprendere il tipo di errore e quale condizione l'ha generato. Tali informazioni e lo stato di errore st_error, permangono finché non viene eseguito l'apposito comando RSERR che li cancella.
La seguente tabella specifica i valori assunti da errcode:

errcode	Descrizione
0	Nessun errore.
1	Errore generico
2	Errore hardware: l'hardware non supporta dispositivi di conteggio assoluto.

Per mezzo del parametro errvalue è possibile ottenere informazioni più dettagliate riguardo l'errore.
Attualmente il parametro errvalue non è utilizzato e vale sempre 0.

8.2 Warnings

Quando l'impostazione di un parametro del device non viene accettata o quando non è possibile eseguire un comando il device segnala questa condizione tramite l'attivazione dello stato st_warning. Il device, inoltre, rende disponibili, tramite i valori sui parametri wrncode e wrnvalue, alcune informazioni per meglio comprendere il tipo di warning e quale condizione l'ha generato. Tali informazioni e lo stato di warning st_warning, permangono finché non viene eseguito l'apposito comando RSWRN che li cancella.
La seguente tabella specifica i valori assunti da wrncode:

wrncode	Descrizione
0	Nessun warning.
1	parametro non accettato: la scrittura su un parametro non è andata a buon fine.
2	comando non eseguito.
3	velocità troppo alta.
4	errore di parità.

Per mezzo del parametro wrnvalue è possibile ottenere informazioni più dettagliate riguardo il warning.

wrnvalue	Descrizione
0	nessuna informazione aggiuntiva riguardo il warning.
1	operazione non abilitata.
2	dato fuori range.